The present invention relates generally to photographic apparatus and, more specifically, to improvements regarding photographic apparatus for handling and processing film units of the self-developing type.
One commercially successful instant film system includes a camera wherein a self-developing film unit is removed manually from the camera following exposure, thereby effecting processing of the exposed unit, indexing of a subsequent film unit, and singulation of the pulled unit.
Examples of such cameras and film are described generally in commonly-assigned U.S. Pat. Nos. 5,870,633; 6,055,380; and, 6,099,172. Film assemblages that are particularly adapted for use in these cameras include an elongated strip containing in an alternating arrangement a plurality of successively aligned and identical film frames. Each of the film frames comprises generally coextensive positive and negative sheets that are generally rectangular in configuration and are in superimposed relationship to one another. In addition, a pair of elongated rails is provided that are sandwiched between the positive and negative sheets. Further included is a rupturable reservoir containing processing fluid at a leading end of the film unit and a trap at the trailing end of the unit. The reservoir includes a weakened portion that ruptures upon the application thereto of predetermined compressive forces that are applied by a pressure applying assembly during film assemblage removal. It is extremely important for the successful development of latent images that the fluid be spread in a relatively uniform layer. It is equally as important that ambient light not interfere or strike the unprocessed latent image before processing is complete as might occur by such light being lightpiped. Light-piping tends to occurs when ambient light travels along a portion of the film extending from the camera and strikes the still unprocessed exposed film in the interior of the camera. In addition, it is highly desirable to prevent against undesired light striking the film if components, such as the film loading door do not properly close.
It has been known to address the problem of non-uniform spreading of processing fluid between superposed sheets of photosensitive material, such as described in, for example, commonly assigned U.S. Pat. No. 2,845,850; and the above-noted crossreferenced patent application. It is also known to address the issues of light-piping. Many known approaches exist, such as is accomplished by a relatively large flap extending over an exterior portion of the camera""s film exit slot; as is described in the last-noted patent application. In addition, there have been numerous efforts to insure that the camera is otherwise light tight particularly in those camera areas that are repeatedly opened and closed by the user, such as the film-loading door. Furthermore, despite the satisfactory results obtained using such past approaches there is, nevertheless, a desire to improve upon heretofore known approaches.
It is an object of the present invention to provide for an improved photographic apparatus and method of processing self-developing film that minimizes image artifacts caused by withdrawing the film from the exit slot at undesired pitch angles, and those caused by light-piping occurring during emergence of the film from the camera as the film is being pulled.
It is a further object of the present invention to provide for an improved photographic apparatus and method of the foregoing type wherein the film assemblage may be manually withdrawn from the slot without diminishing the uniform thickness of the processing fluid layer despite angular pitch changes of the film during withdrawal.
It is another object of the present invention to inhibit lightpiping with structure that covers the emerging film and at the same time includes film engagement members that selectively engage the film and limit the latter""s degree of angular deviancy with respect to a desired horizontal film pulling plane so as not to alter uniform processing fluid thickness.
It is still a further object of the present invention to provide for an improved apparatus and method of foregoing type, which insures lighttight conditions of the camera including about the loading door.
It is still a further object of the present invention to provide for an improved apparatus and method of foregoing type, which is achieved in a simplified construction.
The above and other objects and scope of the present invention will become apparent following reading a detailed description thereof and taken in conjunction with the accompanying drawings in which like reference numerals designate like structure throughout the several views.